Add broadcast and query API for AudioSource.HOTWORD.

- When the AudioSource.HOTWORD input becomes active or is released, send
  a Broadcast with the package name and the new state of the audio input
  to any applications that hold CAPTURE_AUDIO_OUTPUT.
- Store the package name of the application that controls the hOTWORD
  input or set it to null if the input is not in use.
- Add a new method to AudioService to retrieve the package name of the
  application that currently controls the HOTWORD input.

Change-Id: I2f11888f3711d23b6287a4de7b81d361734a8f3b

4 files changed, 127 insertions, 1 deletions

diff --git a/core/java/android/content/Intent.java b/core/java/android/content/Intent.java
index 404564b..c63fe1c 100644
--- a/core/java/android/content/Intent.java
+++ b/core/java/android/content/Intent.java
@@ -2678,6 +2678,45 @@ public class Intent implements Parcelable, Cloneable {
             "android.intent.action.GET_RESTRICTION_ENTRIES";
 
     /**
+     * <p>Broadcast Action: The state of the HOTWORD audio input has changed.:</p>
+     * <ul>
+     *   <li><em>state</em> - A String value indicating the state of the input.
+     *   {@link #EXTRA_HOTWORD_INPUT_STATE}. The value will be one of:
+     *   {@link android.media.AudioRecord#RECORDSTATE_RECORDING} or
+     *   {@link android.media.AudioRecord#RECORDSTATE_STOPPED}.
+     *   </li>
+     *   <li><em>package</em> - A String value indicating the package name of the application
+     *   that currently holds the HOTWORD input.
+     *   {@link #EXTRA_CURRENT_PACKAGE_NAME}
+     *   </li>
+     * </ul>
+     *
+     * <p class="note">This is a protected intent that can only be sent
+     * by the system. It can only be received by packages that hold
+     * {@link android.Manifest.permission#CAPTURE_AUDIO_HOTWORD}.
+     *
+     * @hide
+     */
+    //@SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
+    public static final String ACTION_HOTWORD_INPUT_CHANGED
+            = "com.cyanogenmod.intent.action.HOTWORD_INPUT_CHANGED";
+
+    /**
+     * @hide
+     * Activity to challenge the user for a PIN that was configured when setting up
+     * restrictions. Restrictions include blocking of apps and preventing certain user operations,
+     * controlled by {@link android.os.UserManager#setUserRestrictions(Bundle).
+     * Launch the activity using
+     * {@link android.app.Activity#startActivityForResult(Intent, int)} and check if the
+     * result is {@link android.app.Activity#RESULT_OK} for a successful response to the
+     * challenge.<p/>
+     * Before launching this activity, make sure that there is a PIN in effect, by calling
+     * {@link android.os.UserManager#hasRestrictionsChallenge()}.
+     */
+    public static final String ACTION_RESTRICTIONS_CHALLENGE =
+            "android.intent.action.RESTRICTIONS_CHALLENGE";
+
+    /**
      * Sent the first time a user is starting, to allow system apps to
      * perform one time initialization.  (This will not be seen by third
      * party applications because a newly initialized user does not have any
@@ -3881,6 +3920,15 @@ public class Intent implements Parcelable, Cloneable {
      */
     public static final String EXTRA_THEME_PACKAGE_NAME = "android.intent.extra.PACKAGE_NAME";
 
+    /**
+     * Extra for {@link #ACTION_HOTWORD_INPUT_CHANGED} that provides the state of
+     * the input when the broadcast action was sent.
+     * @hide
+     */
+    public static final String EXTRA_HOTWORD_INPUT_STATE =
+            "com.cyanogenmod.intent.extra.HOTWORD_INPUT_STATE";
+
+
     // ---------------------------------------------------------------------
     // ---------------------------------------------------------------------
     // Intent flags (see mFlags variable).
diff --git a/media/java/android/media/AudioRecord.java b/media/java/android/media/AudioRecord.java
index 27cc220..c1ca2b0 100644
--- a/media/java/android/media/AudioRecord.java
+++ b/media/java/android/media/AudioRecord.java
@@ -903,6 +903,11 @@ public class AudioRecord
                 mRecordingState = RECORDSTATE_RECORDING;
             }
         }
+
+        if (getRecordingState() == RECORDSTATE_RECORDING &&
+                getAudioSource() == MediaRecorder.AudioSource.HOTWORD) {
+            handleHotwordInput(true);
+        }
     }
 
     /**
@@ -946,6 +951,10 @@ public class AudioRecord
             native_stop();
             mRecordingState = RECORDSTATE_STOPPED;
         }
+
+        if (getAudioSource() == MediaRecorder.AudioSource.HOTWORD) {
+            handleHotwordInput(false);
+        }
     }
 
     private final IBinder mICallBack = new Binder();
@@ -962,6 +971,16 @@ public class AudioRecord
         }
     }
 
+    private void handleHotwordInput(boolean listening) {
+        final IBinder b = ServiceManager.getService(android.content.Context.AUDIO_SERVICE);
+        final IAudioService ias = IAudioService.Stub.asInterface(b);
+        try {
+            ias.handleHotwordInput(listening);
+        } catch (RemoteException e) {
+            Log.e(TAG, "Error talking to AudioService when handling hotword input.", e);
+        }
+    }
+
     //---------------------------------------------------------
     // Audio data supply
     //--------------------
diff --git a/media/java/android/media/IAudioService.aidl b/media/java/android/media/IAudioService.aidl
index 0b98e1b..cdcd83c 100644
--- a/media/java/android/media/IAudioService.aidl
+++ b/media/java/android/media/IAudioService.aidl
@@ -227,4 +227,9 @@ interface IAudioService {
     void addMediaPlayerAndUpdateRemoteController(String packageName);
 
     void removeMediaPlayerAndUpdateRemoteController(String packageName);
+
+    void handleHotwordInput(boolean listening);
+
+    String getCurrentHotwordInputPackageName();
+
 }
diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index cde2d7c..e60d9cf 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -59,6 +59,7 @@ import android.media.AudioFormat;
 import android.media.AudioManager;
 import android.media.AudioManagerInternal;
 import android.media.AudioPort;
+import android.media.AudioRecord;
 import android.media.AudioRoutesInfo;
 import android.media.IAudioFocusDispatcher;
 import android.media.IAudioRoutesObserver;
@@ -405,6 +406,15 @@ public class AudioService extends IAudioService.Stub {
      * @see System#MUTE_STREAMS_AFFECTED */
     private int mMuteAffectedStreams;
 
+    /** @see #handleHotwordInput **/
+    private Object mHotwordInputLock = new Object();
+
+    /** The package name of the application that is
+     * currently using the HOTWORD input.
+     */
+    // protected by mHotwordInputLock
+    private String mHotwordAudioInputPackage;
+
     /**
      * NOTE: setVibrateSetting(), getVibrateSetting(), shouldVibrate() are deprecated.
      * mVibrateSetting is just maintained during deprecation period but vibration policy is
@@ -1601,6 +1611,46 @@ public class AudioService extends IAudioService.Stub {
         sendVolumeUpdate(streamType, oldIndex, index, flags);
     }
 
+    /**
+     * Retrieve the package name of the application that currently controls
+     * the {@link android.media.MediaRecorder.AudioSource#HOTWORD} input.
+     * @return The package name of the application that controls the input
+     * or null if no package currently controls it.
+     */
+    public String getCurrentHotwordInputPackageName() {
+        return mHotwordAudioInputPackage;
+    }
+
+    /**
+     * Handle the change of state of the HOTWORD input.
+     *
+     * When the {@link android.media.MediaRecorder.AudioSource#HOTWORD} input is
+     * in use, send a broadcast to alert the new state and store the name of the current
+     * package that controls the input in mHotwordAudioInputPackage.
+     * @param listening Whether the input is being listened to.
+     */
+    public void handleHotwordInput(boolean listening) {
+        synchronized (mHotwordInputLock) {
+            Intent broadcastIntent = new Intent(Intent.ACTION_HOTWORD_INPUT_CHANGED);
+            String[] packages = mContext.getPackageManager().getPackagesForUid(
+                    Binder.getCallingUid());
+            if (packages.length > 0) {
+                if (listening) {
+                    mHotwordAudioInputPackage = packages[0];
+                }
+                broadcastIntent.putExtra(Intent.EXTRA_CURRENT_PACKAGE_NAME, packages[0]);
+            }
+            broadcastIntent.putExtra(Intent.EXTRA_HOTWORD_INPUT_STATE,
+                                     listening ? AudioRecord.RECORDSTATE_RECORDING :
+                                     AudioRecord.RECORDSTATE_STOPPED);
+            // Set the currently listening package to null if listening has stopped.
+            if (!listening) {
+                mHotwordAudioInputPackage = null;
+            }
+            sendBroadcastToAll(broadcastIntent, Manifest.permission.CAPTURE_AUDIO_HOTWORD);
+        }
+    }
+
     /** @see AudioManager#forceVolumeControlStream(int) */
     public void forceVolumeControlStream(int streamType, IBinder cb) {
         synchronized(mForceControlStreamLock) {
@@ -1653,11 +1703,15 @@ public class AudioService extends IAudioService.Stub {
     }
 
     private void sendBroadcastToAll(Intent intent) {
+        sendBroadcastToAll(intent, null);
+    }
+
+    private void sendBroadcastToAll(Intent intent, String receiverPermission) {
         intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
         intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND);
         final long ident = Binder.clearCallingIdentity();
         try {
-            mContext.sendBroadcastAsUser(intent, UserHandle.ALL);
+            mContext.sendBroadcastAsUser(intent, UserHandle.ALL, receiverPermission);
         } finally {
             Binder.restoreCallingIdentity(ident);
         }